There is an increasing demand for radio frequency (RF) communication systems to provide high-speed data transmissions in a reliable manner. In order to enable high-speed data transmission over a wireless channel, which uses limited bandwidth and power, it may be important to increase capacity. The reliability of reception signals may be greatly degraded by fading, shadowing, wave attenuation, interference, etc. An antenna that is capable of multiple input/multiple output (MIMO) operation, without requiring a number of separate antennas and/or separate antenna emitters, that could be reliably and inexpensively manufactured and provide reliable operation may address these problems and provide numerous other advantages.
Typically, MIMO antenna technology uses a spatial multiplexing technique for transmitting data at high speeds without further increasing the system's bandwidth, by using multiple antennas at the transmitter or receiver to transmit different data simultaneously. However, the use of multiple antennas may be expensive in both actual cost and in the footprint and size of the arrangement. Thus, it would be particularly beneficial to provide an antenna that may operate in a MIMO configuration, and particularly in an i×p arrangement (where i is a positive integer greater than 3, and p is some integer greater than 2), allowing operation with multiple streams of RF data from a single compact antenna, and particularly an antenna having a single emitter.
To date, most MIMO antennas have an arrayed antenna structure that uses multiple radiators (emitters), and since a multiple number of radiators are used, there can be interference occurring between the radiators. Such interference can distort the radiating pattern or create a mutual coupling effect among the radiators. In order to minimize interference between radiators, a MIMO antenna may use an isolation element, i.e. a separate feature, or may use a structure in which the radiators are widely separated from one another. In these cases, providing the desired isolation basically involves providing a sufficient distance between two antennas, even in cases where a separate isolation element is used. However, since the demand for smaller terminals is an ongoing requirement, and since providing a sufficient distance between multiple antennas not only is very difficult but also runs contrary to providing smaller terminal sizes, there is a need for an isolation technique that can be applied for multiple antennas that are positioned relatively closely to one another.
Households and businesses in areas without wired connections (e.g., in regions that cannot be reached via conventional communication media, such as optical cables, copper cables, and/or other fixed wire-based technologies) may rely on fixed wireless services for some of these services (e.g., broadband access). Fixed wireless services can be made more attractive to customers by effectively leverage existing customer premises equipment (CPE).
There is a growing need to develop systems to deliver broadband to remote and under-served regions, for which traditional broadband (e.g., wired or cabled delivery) is not available or possible. Delivering high performance networking in underserved and underpenetrated regions is challenging because of the lack of durable and powerful systems, including antenna-based systems, capable of operating with sufficient flexibility to provide point-to-point as well as point-to-multipoint communication between client stations (e.g., home or business locations) and an internet service provider, including wireless internet service providers.
To keep the costs of these devices down, so that they may be provided to even underserved communities at a reasonable price, the antennas are produced to be reliable, easy to manufacture, and easy to use. In addition, these antennas have a sufficiently large bandwidth in an appropriate band. Further, the devices are compact, yet have minimal line radiation and other sources of noise.
The systems may include user-friendly devices including amplifying, broadband radios/antenna that are robust (including for use in outdoor regions), and easy to install and use. Described herein are antennas that may be used for MIMO operation that may resolve the problems described above and provide an antenna having a single emitter adapted to emit three or more independent beams using a patterned antenna radiating emitter. These antennas may therefore also be referred to as multi-focal-point antennas. As described in greater detail below, the antennas described herein can provide isolation of the three or more beams even using a single (relatively small) emitter.
The devices described herein may also be of particular use to deliver broadband data services to remote and under-served regions, for which traditional broadband (e.g., wired or cabled delivery) is not available or possible. Delivering high performance networking in underserved and underpenetrated regions is challenging because of the lack of durable and powerful systems, including antenna-based systems, capable of operating with sufficient flexibility to provide point-to-point as well as point-to-multipoint communication between client stations (e.g., home or business locations) and an internet service provider, including wireless internet service providers. In addition, the systems described herein may also be of particular use when delivering information in congested urban areas, which may otherwise provide numerous barriers to transmission. Thus, described herein are apparatuses (e.g., devices and systems) and methods of operating them that may address the issue raised above.